pruriens [L.] DC.), jack bean, and wild tamarind (Lysiloma latisiliquum L.). Similarly,
crabgrass and barnyard grass population in soybean was reduced when barley was
grown as a cover crop [125]. Hyacinth bean and jack bean as cover crop can efficiently
control the mission grass (Pennisetum polystachion L.), a noxious weed in rubber
(Hevea brasiliensis Mull. Arg.) plantations [126]. Red spider lily (Lycoris radiate L.)
can be grown as a cover crop as its dead leaves have lycorine (0.08%) allelochemical,
which can reduce the germination and root/shoot growth of rice weeds [127]. Leaf
water extracts of the cover crops [e.g., trefoil (Oxalis brasiliensis L.)] have been
reported to decrease the growth of lettuce, star-of-Bethlehem (Ornithogalum
umbellatum L.), red spider lily, European pennyroyal (Mentha pulegium L.), creeping
thyme (Thymus serpyllum L.), moss pink (Phlox subulata L.), and chamomile
(Chamaemelum nobile L.) [128, 129].
Cover crops also suppress weed in conservation tillage systems. For example,
rye as a cover crop can control the weed population in soybean crop in no-till system
[113]. Use of rye and wheat as cover crop in cotton also helps to control diverse weeds
[114]. Cover crops have also been reported to decrease the biomass of goosegrass,
pitted white morning glory (Ipomoea lacunosa L.), and palmer amaranth (Amaranthus
palmeri S. Watson) with decreased seed bank in the soil [74]. The cover crop residues
enhance the nutrient level and allelochemicals in the soil that discourage the plant
pests, mainly the diseases caused by the soilborne pathogens [130, 131].
3.4
Mulching and Soil Incorporation of the Allelopathic Crop
Residues
Use of allelopathic mulches is also a pragmatic way to control weeds in field
crops (Table 2; [17, 105, 76, 132]). The allelopathic mulches decrease the seed
Table 2 (continued)
Weed species
Allelopathic
source
Application
mode
Weed dry
weight
reduction (%) References
Common lamb’s quarter,
velvetleaf (Abutilon
theophrasti Medik)
Rye crop
Cover crop
–
[113]
Goosegrass, Palmer amaranth
(Amaranthus palmeri S.
Wats), pitted white morning
glory
Wheat crop
Cover crop
–
[114]
Littleseed canarygrass,
common lamb’s quarter,
toothed dock, fumitory
Sorghum
crop
Soil
incorporation
42–56
[115]
Horse purslane, field
bindweed, Bermuda grass,
purple nutsedge
Sorghum
crop
Surface
mulch
50–96.6
[116]
554
A. Nawaz et al.
crabgrass and barnyard grass population in soybean was reduced when barley was
grown as a cover crop [125]. Hyacinth bean and jack bean as cover crop can efficiently
control the mission grass (Pennisetum polystachion L.), a noxious weed in rubber
(Hevea brasiliensis Mull. Arg.) plantations [126]. Red spider lily (Lycoris radiate L.)
can be grown as a cover crop as its dead leaves have lycorine (0.08%) allelochemical,
which can reduce the germination and root/shoot growth of rice weeds [127]. Leaf
water extracts of the cover crops [e.g., trefoil (Oxalis brasiliensis L.)] have been
reported to decrease the growth of lettuce, star-of-Bethlehem (Ornithogalum
umbellatum L.), red spider lily, European pennyroyal (Mentha pulegium L.), creeping
thyme (Thymus serpyllum L.), moss pink (Phlox subulata L.), and chamomile
(Chamaemelum nobile L.) [128, 129].
Cover crops also suppress weed in conservation tillage systems. For example,
rye as a cover crop can control the weed population in soybean crop in no-till system
[113]. Use of rye and wheat as cover crop in cotton also helps to control diverse weeds
[114]. Cover crops have also been reported to decrease the biomass of goosegrass,
pitted white morning glory (Ipomoea lacunosa L.), and palmer amaranth (Amaranthus
palmeri S. Watson) with decreased seed bank in the soil [74]. The cover crop residues
enhance the nutrient level and allelochemicals in the soil that discourage the plant
pests, mainly the diseases caused by the soilborne pathogens [130, 131].
3.4
Mulching and Soil Incorporation of the Allelopathic Crop
Residues
Use of allelopathic mulches is also a pragmatic way to control weeds in field
crops (Table 2; [17, 105, 76, 132]). The allelopathic mulches decrease the seed
Table 2 (continued)
Weed species
Allelopathic
source
Application
mode
Weed dry
weight
reduction (%) References
Common lamb’s quarter,
velvetleaf (Abutilon
theophrasti Medik)
Rye crop
Cover crop
–
[113]
Goosegrass, Palmer amaranth
(Amaranthus palmeri S.
Wats), pitted white morning
glory
Wheat crop
Cover crop
–
[114]
Littleseed canarygrass,
common lamb’s quarter,
toothed dock, fumitory
Sorghum
crop
Soil
incorporation
42–56
[115]
Horse purslane, field
bindweed, Bermuda grass,
purple nutsedge
Sorghum
crop
Surface
mulch
50–96.6
[116]
554
A. Nawaz et al.